Cui Ziyin, Dang Guanghui, Song Ningning, Cui Yingying, Li Zhe, Zang Xinxin, Liu Hongxiu, Wang Zhongxing, Liu Siguo
State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.
Front Microbiol. 2020 Sep 11;11:2204. doi: 10.3389/fmicb.2020.532371. eCollection 2020.
Patatin-like phospholipases (PLPs) are important virulence factors of many pathogens. However, there are no prevailing studies regarding PLPs as a virulence factor of (Mtb). Analysis of Rv3091, a putative protein of Mtb, shows that it belongs to the PLPs family. Here, we cloned and expressed the gene in and, subsequently, conducted protein purification and characterization. We show that it possesses phospholipase A, phospholipase A, and lipase activity. We confirm the putative active site residues, namely, Ser214 and Asp407, using site directed mutagenesis. The Rv3091 is an extracellular protein that alters the colony morphology of . The presence of Rv3091 enhances the intracellular survival capability of in murine peritoneal macrophages. Additionally, it promotes phagosomal escape from macrophages. Moreover, Rv3091 significantly increased the survival of and aggravated lesions in C57BL/6 J murine lungs . Taken together, our results indicate that Rv3091 as an extracellular PLP that is critical to the pathogenicity of mycobacterium as it allows mycobacterium to utilize phospholipids for its growth and provides resistance to phagosome killing, resulting in its enhanced intracellular survival.
类Patatin磷脂酶(PLPs)是许多病原体的重要毒力因子。然而,关于PLPs作为结核分枝杆菌(Mtb)毒力因子的研究尚无定论。对Mtb的一种假定蛋白Rv3091的分析表明,它属于PLPs家族。在此,我们在大肠杆菌中克隆并表达了该基因,随后进行了蛋白质纯化和特性鉴定。我们发现它具有磷脂酶A、磷脂酶A和脂肪酶活性。我们通过定点诱变确定了假定的活性位点残基,即Ser214和Asp407。Rv3091是一种细胞外蛋白,可改变耻垢分枝杆菌的菌落形态。Rv3091的存在增强了耻垢分枝杆菌在小鼠腹腔巨噬细胞中的细胞内存活能力。此外,它促进耻垢分枝杆菌从巨噬细胞的吞噬体逃逸。此外,Rv3091显著提高了结核分枝杆菌在C57BL/6 J小鼠肺部的存活率并加重了病变。综上所述,我们的结果表明,Rv3091作为一种细胞外PLP,对分枝杆菌的致病性至关重要,因为它使分枝杆菌能够利用磷脂进行生长,并提供对吞噬体杀伤的抗性,从而提高其细胞内存活能力。